Irrigation Water Usage for Aquaculture in Phan Thong District, Chon Buri Province

Abstract

This survey research method-based study aimed to investigate water usage in aquaculture in an area that received water from an irrigation canal in Phan Thong district, Chon Buri. Water usage per crop was investigated in 6 ponds in which tilapia fish and white-legged shrimps were grown and in another six ponds in which a polyculture of fish and white-legged shrimp were grown. In addition, the amount of water received from the irrigation canal over the period January to December 2018 was investigated. A total of 78 farmer representatives were interviewed using structured interview methods to study water usage patterns. In addition, related information from the Department of Fisheries was collected. The study found that raising tilapia fish together with white-legged shrimp used 12,133,136.00 m³.crop^-1 of water, whereas raising the polyculture of fish together with white-legged shrimp used 2,022,006.33 m³.crop^-1 of water. The results also showed that the highest water usage occurred in January.
The amount of water received from the irrigation system in the month of April was 9,398,735.28 m³, which was
the highest monthly figure over the time of the study. The study found that the amount of water used for aquaculture in January, August, October and November accounted for 40.48%, 47.2%, 24.4% and 60.4% respectively of
the amount of water received. This result showed that the use of water from irrigation systems for aquaculture was relatively large. However, the amount of water received per cycle was sufficient for the fish culture in this study area. In the event of a shortage of water, 55.1% of farmers will reduce the level of water filled into the culture ponds, 32.1% of farmers will alternate water pumping and 12.8% will reduce the number of aquaculture ponds used whilst maintaining the same stocking density.